CN106415352A

CN106415352A - Telecentric optical lens

Info

Publication number: CN106415352A
Application number: CN201480078616.9A
Authority: CN
Inventors: 李家英; 周朝明; 孙博; 陈玉庆; 高云峰
Original assignee: Han s Laser Technology Industry Group Co Ltd
Current assignee: Han s Laser Technology Co Ltd; Han s Laser Technology Industry Group Co Ltd
Priority date: 2014-09-17
Filing date: 2014-09-17
Publication date: 2017-02-15
Anticipated expiration: 2034-09-17
Also published as: JP2017520023A; WO2016041161A1; DE112014006698B4; US20170248776A1; US9897787B2; CN106415352B; JP6301506B2; DE112014006698T5

Abstract

A telecentric optical lens (100), comprising a first lens (L1) to a fifth lens (L5) arranged sequentially and co-axially along the direction of transmission of the incident light ray; the first lens (L1) is a plano-concave negative lens; the second lens (L2) is a meniscus negative lens; the third lens (L3) is a meniscus negative lens; the fourth lens (L4) is a biconvex positive lens; and the fifth lens (L5) is a plano-concave negative lens; the arrangement and design parameters of the first lens (L1) to the fifth lens (L5) of the telecentric optical lens (100) allow said telecentric optical lens (100) to achieve a telecentric effect, and simultaneously satisfy achromatic and relatively large aperture requirements.

Description

Telecentric optical lens

[ technical field ] A method for producing a semiconductor device

The invention relates to an optical lens, in particular to a telecentric optical lens.

[ background of the invention ]

With the development of laser processing technology, particularly the development of optical systems, a general f-theta (scanning objective) optical lens is designed by a combination of a plurality of optical lenses to achieve a telecentric effect, i.e., a telecentric optical lens. However, it is difficult for the telecentric optical lens to satisfy both achromatization and a relatively large aperture requirement due to the setting of optical parameters of the individual optical lenses of the telecentric optical lens and the pitch design between the individual lenses.

[ summary of the invention ]

In view of this, there is a need to provide a telecentric optical lens that can meet both achromatic and relatively large aperture requirements.

A telecentric optical lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a fourth lens, a fifth lens, a sixth lens, a fifth lens, a sixth lens, a tenth lens, a fifth lens, a sixth lens, a fifth lens, The sixth curved surface and the ninth curved surface are both convex towards the incident light transmission direction, the seventh curved surface is convex facing the incident light, the second curved surface and the tenth curved surface are planes, the curvature radius of the first curved surface is-50 +/-5% mm, the curvature radii of the third curved surface to the ninth curved surface are-121 +/-5%, -80.1 +/-5%, -606 +/-5%, -100 +/-5%, 250 +/-5%, -200 +/-5%, -150 +/-5%, and the unit is mm.

In one embodiment, the central thicknesses of the first lens to the fifth lens are 5 +/-5%, 10 +/-5%, 26 +/-5%, 28 +/-5%, 4 +/-5% in millimeter sequentially.

In one embodiment, the distances on the optical axis between the second curved surface and the third curved surface, between the fourth curved surface and the fifth curved surface, between the sixth curved surface and the seventh curved surface, and between the eighth curved surface and the ninth curved surface are respectively 7 ± 5%, 0.5 ± 5%, 12 ± 5%, and the unit is millimeter.

In one embodiment, the ratio of the refractive index to the abbe number of the first lens is (1.8/26) ± 5%, the ratios of the refractive indices to the abbe numbers of the second lens to the fourth lens are (1.7/50) ± 5%, and the ratio of the refractive index to the abbe number of the fifth lens is (1.6/35) ± 5%.

In one embodiment, the outer diameters of the first lens to the fifth lens are 94 +/-5%, 100 +/-5%, 120 +/-5%, 140 +/-5% in sequence and are in millimeters.

In one embodiment, the telecentric optical lens further comprises a sixth lens, the sixth lens comprises an eleventh curved surface as a light incident surface and a twelfth curved surface as a light exit surface, the tenth curved surface and the eleventh curved surface are spaced from each other by 2 ± 5% of a millimeter on the optical axis, and the sixth lens is a planar lens.

In one embodiment, the sixth lens is a protective glass, the central thickness of the protective glass is 4 +/-5% mm, the ratio of the refractive index to the Abbe number of the sixth lens is (1.5/64) +/-5%, and the outer diameter of the sixth lens is 140 +/-5% mm.

In one embodiment, the telecentric optical lens has a focal length of 170mm, an entrance pupil diameter of 30mm, a working wavelength of 1064-630 nm, and a maximum working area of 104 × 104 mm.

Through the arrangement and parameter design of the first lens, the second lens and the fifth lens of the telecentric optical lens, the telecentric optical lens can simultaneously meet the requirements of achromatism and relative large aperture.

[ description of the drawings ]

The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings. Like reference numerals refer to like parts throughout the drawings, and the drawings are not intended to be drawn to scale in actual dimensions, emphasis instead being placed upon illustrating the principles of the invention.

Fig. 1 is a schematic structural diagram of a telecentric optical lens in an embodiment.

FIG. 2 is a speckle pattern of the telecentric optical lens of the embodiment shown in FIG. 1.

Fig. 3 is a graph of the modulation transfer function m.t.f of the telecentric optical lens of the embodiment shown in fig. 1.

Fig. 4 is an astigmatism diagram of the telecentric optical lens of the embodiment shown in fig. 1.

Fig. 5 is a distortion diagram of the telecentric optical lens of the embodiment shown in fig. 1.

[ detailed description ] embodiments

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, but rather should be construed as broadly as the present invention is capable of modification in various respects, all without departing from the spirit and scope of the present invention.

It should be noted that the light propagation direction in this specification is from the left side to the right side of the drawing. The positive and negative of the curvature radius are based on the intersection point of the spherical center position of the curved surface and the main optical axis, and the curvature radius is negative when the spherical center of the curved surface is left at the point; conversely, if the center of the curved surface is on the right side of the point, the radius of curvature is positive. In addition, the object space is located on the left side of the lens, and the image space is located on the right side of the lens. A positive lens refers to a lens having a center thickness greater than the edge thickness, and a negative lens refers to a lens having a center thickness less than the edge thickness.

Fig. 1 is a schematic diagram of a telecentric optical lens 100 in one embodiment, and for convenience of illustration, only the parts relevant to the present invention are shown. The telecentric optical lens 100 includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5 and a sixth lens L6 which are coaxially arranged in order along the transmission direction of incident light. The first lens element L1 is a concave negative lens element, the second lens element L2 is a negative meniscus lens element, the third lens element L3 is a negative meniscus lens element, the fourth lens element L4 is a positive biconvex lens element, the fifth lens element L5 is a negative concave negative lens element, and the sixth lens element L6 is a planar lens element. The first lens L1 includes a first curved surface S1 and a second curved surface S2, the second lens L2 includes a third curved surface S3 and a fourth curved surface S4, the third lens L3 includes a fifth curved surface S5 and a sixth curved surface S6, the fourth lens L4 includes a seventh curved surface S7 and an eighth curved surface S8, the fifth lens L5 includes a ninth curved surface S9 and a tenth curved surface S10, the sixth lens L6 includes an eleventh curved surface S11 and a twelfth curved surface S12, two curved surfaces of each lens are respectively a light incident surface and a light exit surface, and the first curved surface S1 to the twelfth curved surface S12 are sequentially arranged in a direction in which incident light is transmitted. The first curved surface S1, the second curved surface S2, the third curved surface S3, the fourth curved surface S4, the fifth curved surface S5, the sixth curved surface S6, and the ninth curved surface S9 have the same bending direction, and are convex toward the incident light transmission direction (i.e., the object side), while the seventh curved surface S7 is convex toward the incident light direction (i.e., the image side). The tenth curved surface S10, the eleventh curved surface S11, and the twelfth curved surface S12 are all planar. In the present embodiment, the sixth lens L6 is a cover glass. It is understood that the sixth lens L6 may be omitted.

In addition, the inventors have designed the following respective structural parameters of the above five lenses. Specifically, the method comprises the following steps:

the ratio of the refractive index to the abbe number of the first lens L1 is (1.8/26) ± 5%. The first curved surface S1 of the first lens L1 is convex toward the image side and has a radius of curvature of-50 mm. The second curved surface S2 is a plane surface with a radius of curvature of ∞, the center thickness D1 of the first lens L1 (i.e., the thickness of the lens on the optical axis) is 5mm, and the outer diameter D1 of the first lens L1 is 94 mm. Each of the above parameters of the first lens L1 has a 5% tolerance range, i.e., each parameter is allowed to vary within ± 5%.

The ratio of the refractive index to the abbe number of the second lens L2 is (1.7/50) ± 5%. The third curved surface S3 of the second lens L2 is convex toward the image side with a radius of curvature of-121 mm, and the fourth curved surface S4 is convex toward the image side with a radius of curvature of-80.1 mm. The center thickness d3 of the second lens L2 was 10mm, the outer diameter of the second lens was 100mm, and the above parameters of the second lens L2 were within a tolerance range of 5%.

The ratio of the refractive index to the abbe number of the third lens L3 is (1.7/50) ± 5%. The fifth curved surface S5 of the third lens L3 is convex toward the image side with a radius of curvature of-606 mm, and the sixth curved surface S6 is convex toward the image side with a radius of curvature of-100 mm. The center thickness d5 of the third lens L3 was 26mm, the outer diameter of the third lens was 120mm, and the above parameters of the third lens L3 were within a tolerance range of 5%.

The ratio of the refractive index to the abbe number of the fourth lens L4 is (1.7/50) ± 5%. The seventh curved surface S7 of the fourth lens L4 is convex toward the object side and has a radius of curvature of 250 mm. The eighth curved surface S8 is convex toward the image side with a radius of curvature of-200 mm. The center thickness d7 of the fourth lens L4 is 28mm, the outer diameter of the fourth lens is 140mm, and the tolerance range of 5% exists in each of the above parameters of the fourth lens L4.

The ratio of the refractive index to the abbe number of the fifth lens L5 is (1.6/35) ± 5%. The ninth curved surface S9 of the fifth lens L5 is convex toward the image side, and has a radius of curvature of-150 mm. The tenth curved surface S10 is a plane and has a curvature radius of ∞. The fifth lens L5 has a center thickness d9 of 4mm and an outer diameter of 140 mm. Each parameter of the fifth lens L5 has a tolerance range of 5%.

The ratio of the refractive index to the abbe number of the sixth lens L6 is (1.5/64) ± 5%. The eleventh curved surface S11 and the twelfth curved surface S12 of the sixth lens element L6 are both planar and have a radius of curvature of ∞. The center thickness d11 of the sixth lens L6 was 4mm, the outer diameter thereof was 140mm, and each parameter of the sixth lens L6 had a tolerance range of 5%.

In addition, the inventors designed the distance between the adjacent lenses as follows. Specifically, the distance d2 between the exit surface (second curved surface S2) of the first lens L1 and the entrance surface (third curved surface S3) of the second lens L2 on the optical axis is 7mm, and the tolerance is 5%. The distance d4 between the exit surface (fourth curved surface S4) of the second lens L2 and the entrance surface (fifth curved surface S5) of the third lens L3 on the optical axis is 0.5mm, and the tolerance is 5%. The distance d6 between the exit surface (sixth curved surface S6) of the third lens L3 and the entrance surface (seventh curved surface S7) of the fourth lens L4 on the optical axis is 0.5mm, and the tolerance is 5%. The distance d8 between the exit surface (eighth curved surface S8) of the fourth lens L4 and the entrance surface (ninth curved surface S9) of the fifth lens L5 on the optical axis is 12mm, and the tolerance is 5%. The distance d10 between the exit surface (tenth curved surface S10) of the fifth lens L5 and the entrance surface (eleventh curved surface S11) of the sixth lens L6 on the optical axis is 2mm, and the tolerance is 5%.

After the design, the optical parameters of the telecentric optical lens 100 are as follows: the focal length is 170mm, the diameter of the entrance pupil is 30mm, the working wavelength is 1064 nm-630 nm, and the maximum working area can reach 104 x 104 mm. The experimental test effect of the telecentric optical lens 100 is shown in fig. 2-5.

FIG. 2 is a geometric aberration diagram of telecentric optical lens 100 shown in FIG. 1, wherein DBJ represents the angle of view in degrees; IMA denotes the imaging diameter of the image plane in millimeters. The scale length of 100mm is shown in fig. 2. According to the diffuse spot shown in fig. 2, it can be seen that the scattering range of the focused light spot of the telecentric optical lens 100 is small, the energy of the focused point is concentrated, and the on-axis and off-axis aberrations are well corrected, so that the ideal resolution is achieved. The geometrical circle of confusion of all the fields of view is about 0.01mm, and the ideal degree is also achieved.

Fig. 3 is a modulation transfer function (m.t.f) diagram of the telecentric optical lens 100 of the embodiment shown in fig. 1, wherein the abscissa represents resolution in line pairs/mm; TS denotes the field of view in degrees. When the resolution reaches 20 line pairs, the M.T.F is about 0.5, and the requirements of laser processing can be completely met.

Fig. 4 is an astigmatism diagram of telecentric optical lens 100 in the embodiment shown in fig. 1. The ordinate + Y in fig. 4 represents the size of the field of view, and the abscissa has units of millimeters. Fig. 5 is a distortion diagram of telecentric optical lens 100 in the embodiment shown in fig. 1. The ordinate + Y in fig. 5 represents the size of the field of view, and the abscissa unit is a percentage. As can be seen from FIGS. 4-5, the axial chromatic aberration Δ CI of the telecentric optical lens 100 is approximately equal to 0.15, and the magnification chromatic aberration Δ CII is approximately equal to 0, which has reached an ideal degree.

In summary, the arrangement and parameter design of the first to fifth lenses of the telecentric optical lens 100 can make the telecentric optical lens 100 achieve telecentric effect, and satisfy the requirements of achromatism and relative large aperture.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

A telecentric optical lens is characterized by comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a fourth lens, a fifth lens, a sixth lens, a fifth lens, a tenth lens, a fourth lens, a fifth lens, a sixth lens, a tenth lens, a light incident surface and a light emergent surface, wherein the two lens surfaces are respectively the light incident surface and the light emergent surface, the first curved surface, the third curved surface, the fourth curved surface, the fifth lens, the fourth lens, the fifth lens, the fourth, The fifth curved surface, the sixth curved surface and the ninth curved surface are all convex towards the incident light transmission direction, the seventh curved surface is convex facing the incident light, the second curved surface and the tenth curved surface are planes, the curvature radius of the first curved surface is-50 +/-5% mm, the curvature radius of the third curved surface to the ninth curved surface is-121 +/-5%, -80.1 +/-5%, -606 +/-5%, -100 +/-5%, 250 +/-5%, -200 +/-5%, -150 +/-5%, and the unit is mm.
A telecentric optical lens system as in claim 1, wherein the central thicknesses of the first through fifth lenses are sequentially 5 ± 5%, 10 ± 5%, 26 ± 5%, 28 ± 5%, 4 ± 5%, in millimeters.
A telecentric optical lens according to claim 1, wherein the distances on the optical axis between the second curved surface and the third curved surface, between the fourth curved surface and the fifth curved surface, between the sixth curved surface and the seventh curved surface, and between the eighth curved surface and the ninth curved surface are respectively 7 ± 5%, 0.5 ± 5%, 12 ± 5%, in millimeters.
A telecentric optical lens according to claim 1, wherein the ratio of the refractive index to the abbe number of the first lens is (1.8/26) ± 5%, the ratios of the refractive indices to the abbe numbers of the second to fourth lenses are (1.7/50) ± 5%, and the ratio of the refractive index to the abbe number of the fifth lens is (1.6/35) ± 5%.
A telecentric optical lens according to claim 1, wherein the outer diameters of the first through fifth lenses are 94 ± 5%, 100 ± 5%, 120 ± 5%, 140 ± 5% in order, and have the unit of millimeter.
A telecentric optical lens according to claim 1, wherein the telecentric optical lens further comprises a sixth lens, the sixth lens comprises an eleventh curved surface as a light incident surface and a twelfth curved surface as a light exit surface, the tenth curved surface and the eleventh curved surface are spaced apart from each other by 2 ± 5% mm on the optical axis, and the sixth lens is a planar lens.
A telecentric optical lens according to claim 6, wherein the sixth lens is a cover glass with a central thickness of 4 ± 5% mm, the sixth lens has a ratio of refractive index to Abbe number of (1.5/64) ± 5%, and the sixth lens has an outer diameter of 140 ± 5% mm.
A telecentric optical lens according to claim 1 wherein the telecentric optical lens has a focal length of 170mm, an entrance pupil diameter of 30mm, a working wavelength of 1064-630 nm, and a maximum working area of 104 x 104 mm.